The present invention relates to a device for cleaning a roller of a rotary printing press. At least one rotating cleaning element, whose axis of rotation is not parallel with the axis of rotation of the roller to be cleaned, is arranged adjacent that roller. Several cleaning elements, having opposite directions of rotation, can be used.
A device for cleaning rollers is known from EP 0 693 378 B1. A brush roller is guided along the roller to be cleaned, and a cleaning fluid is simultaneously introduced into the inlet gap between the two rollers. This prior art device contains a reservoir for cleaning fluid and a catch basin for dirt particles to be removed.
A printing plate cleaning device is known from U.S. Pat. No. 5,148,746. A rotatable brush, in the shape of a truncated cone, and which can be moistened on the exterior, can be placed obliquely, i.e. at an acute angle in respect to the radial direction, against the plate cylinder, so that only a portion of the brush is in contact with the plate surface. In addition, the edge zone of the brush is beveled in such a way that a section of the brush in the shape of an arc of a circle can be brought into contact with the plate surface.
EP 0 747 217 A2 discloses a cleaning device for cylinders of printing presses. Two rotating brushes, which are offset in respect to each other in the circumferential direction of the cylinder, are provided.
The object of the present invention is based on providing a device for cleaning a roller of a rotary printing press.
In accordance with the present invention, this object is attained by using several rotating cleaning elements to clean the roller. These rotating cleaning elements each have an axis of rotation that is not parallel with the axis of rotation of the roller to be cleaned. The several rotating cleaning elements may have opposite directions of rotation with respect to each other.
The advantages which can be obtained by the present invention rest, in particular, in that an evenly cleaned surface of the rollers or cylinders is obtained. Accumulations of ink or dirt are mechanically removed, except for a thin layer, during either running or standstill of the press. In case of intense soiling, it is possible to apply a cleaning fluid, and the rollers can also be additionally cleaned by the rotating brushes.
Furthermore, it is advantageous, in connection with the present invention, that it is possible to apply an ink separating agent shortly prior to the start of printing. The creation of paper waste, which must be disposed of as special waste, is prevented by use of the cleaning device in accordance with the present invention. Moreover, by removing or preventing the accumulation of dirt on the roller, which roller may be, for example a paper guide roller, the creation of creases in the paper web is prevented.
Finally, it is also advantageous that a paper guide roller, which cannot be driven, can be brought to the required circumferential speed by the auxiliary drive mechanism, for example prior to drawing in a paper web.